1. Field of the Invention
The invention pertains to a radiology installation.
A radiology installation, especially for radioscopy or radiography comprises a large number of instruments which are connected with one another according to requirements. For example, for radioscopy, an X-ray generator, an image intensifier tube, a video camera and a television receiver or monitor are used; for radiography, instead of a video camera and a television monitor, a photographic camera with a film-changing device. When a specified type of examination is being made, a number of instruments are put into operation while the others are out of action, and special connections are set up among the instruments in operation. Thus, for each type of use, the installation is given a specified configuration. To make it possible to change the configuration instantaneously, the installation is often provided with a complex wiring system.
2. Description of the Prior Art
To simplify the assembly, a radiology installation has been proposed in which the X-ray generator is connected with the other instruments in a closed loop where the data is transmitted from one instrument to another by means of an optic fiber. When an instrument is not used or when it has failed, the information is shunted by a change-over switch so as to keep the loop closed.
This installation of the prior art has limitations which can entirely eliminate the advantage gained by simplified wiring. It has been especially observed that when there is a large flow of data to be transmitted between two instruments, the line forming the enclosed loop may be saturated and may simultaneously prevent a large flow of data among other instruments.
3. Summary of the Invention
The invention removes these disadvantages.
According to the invention, the data signals among the instruments of the installation flow along at least two loops which are connected to each other. With an installation of this type, the data can flow simultaneously at a high rate in two distinct loops, and two instruments located in two different loops can be made to communicate with each other.
For example, an image-processing operation recorded in a digital processing instrument may require an exchange of data at a high rate between a control desk and this instrument. This is especially so in the use of a dialogue device such as a tactile screen, a "mouse" or a joystick. With the invention, if the controls of the camera, the image intensifier tube and the image collimator are in a separate loop from the one in which the digital processing instrument is located, it is possible to perform a radiographic operation at the same time as an image processing operation.
In one embodiment, there is provision for a main loop to which the secondary or specialized loops are connected.
In this case, it is possible to assign, to each secondary loop, a monitoring and control device for all the instruments of this loop, this device being at the node between the secondary loop and the main loop.
A secondary loop comprises, for example, the positioning controls for the instruments in the radiology room, namely the patient-bearing and the support, generally hoop-shaped, of the unit formed by the X-ray tube and the detectors. Another secondary or specialized loop is assigned to the control of the image-forming devices such as a photographic camera or a video camera.
For an installation according to the invention, the use of an HDLC (high level data link control) type of communications protocol has been found to be particularly advantageous.
To make the installation of the invention, in one example, a communications and processing device is assigned to each instrument, and this device comprises, separately, a device for handling communications with the other instruments and a circuit for processing messages intended for the instrument or coming from the instrument.
The communications-handling circuit is, for example, a circuit comprising a change-over switch made up of a single switch in parallel which closes when a hitch is detected in the corresponding instrument.
The signals in each loop are of the electrical or optical type.
In the preferred embodiment of the invention, a loop, known as the main loop, has a central handling unit which, whenever the installation becomes powered, determines the configuration of this installation, i.e. it determines the loop in which each instrument is placed and retains this configuration in memory, this determining operation being performed with the help of ancillary handling units, which are located at the junctions between the neighboring loops and which transmit, to the central handling unit, the list of instruments connected to the loop that is furthest from the main loop.
With an installation of this type, the communications path between two instruments is determined automatically at each use, without its depending on the connection. For, when a first instrument in a first loop has to communicate with a second instrument in a second loop, which is distinct from the first one, the first instrument is made to transmit a message on its loop and this message is received by the ancillary handling unit of this loop, which memorizes the configuration of the first loop and that of the neighboring loop and which thus directs the message towards this neighboring loop. If the second instrument is not in this neighboring loop, the message is transmitted by other ancillary handling units to the nodes between this neighboring loop and another loop, and so on until the second loop and the second instrument are reached.
Furthermore, with a communications and processing device assigned to each instrument as well as with a central handling unit and ancillary handling units at each node, the communications and processing device of each instrument may be of an identical nature for all the instrument, namely it may be independent of the type of instrument and the configuration of the installation, thus providing not only for lower costs but also for modifying the configuration by simple modifications of the connections between instruments without any other modifications since, as indicated above, the configuration is determined whenever the power is turned on and the communications path between instruments is set up automatically.